Electronically controlled microfilm photographic image utilization device

ABSTRACT

An electronically controlled photographic image utilization device is arranged to transport a roll of microfilm having all images printed thereon in separate photographic areas, each area being arranged in a microfiche-type format. The photographic image utilization device has an automatic call-up feature so that any given photographic area may be selected in a first dimension and projected responsive to the push of a button, the operation of a rotary switch or both. A special bar code is printed along the edge of the film and used in conjunction with a closed loop film control system to eliminate the need for precise, clock-controlled synchronization between the film transport and the code reading. Preferably, the bar code is read by optical electronic sensors. Responsive thereto, the electronic control system accurately positions a selected photographic image, on the microfilm, within a viewing area. Thereafter, and while the film transport is being held stationary, any image on the microfilm may be selected for projection by a manual movement in second and third dimensions of a simple lens positioning mechanism which is small, compact, and easily moved. The reader may also be operated manually so that the automatic controls may be bypassed, if desired.

This is a division of application Ser. No. 711,180, filed Aug. 3, 1976,now U.S. Pat. No. 4,110,020.

This invention relates to microfilm photographic image utilizationdevices and more particularly to photographic image utilization devicesadapted to transport a roll of film having a plurality of microficheprinted thereon.

The term "photographic image utilization device" is used herein to meanany kind of equipment which is able to use the images that may beselected and projected by the inventive structure. For example, thisequipment might be a mirofilm projector, reader, printer, or the like.

A microfiche is a well known photographic device wherein a plurality ofimages are conventionally microphotocopies in an orthogonal array on asmall sheet film. Usually, the film is somewhat in the nature of a filecard, such as approximately 105 mm.×148 mm. Conventionally, an operatorholds, handles or moves these cards, on an individual basis. Therefore,they may become lost, damaged, destroyed, or refiled out of order.

Sometimes, microfiche contain information which must be continuouslyupdated as the recorded information becomes obsolete or is superseded.If a large file of microfiche must be updated on a continuous basis, asubstantial amount of time and labor is required, and filing mistakesare often made. Moreover, there are costs in copying and manipulatingindividual sheets of film which are not incurred when copying ormanipulating rolls of film.

Yet another problem centers about control over a microfiche file. Thereare many times and conditions when a company, for example, wishes toissue a new edition of microfiche with an assurance that it will beproperly filed and used by employees at many widely scattered points.Also, the company would want to preclude unauthorized removal ofindividual microfiche from a company file. There may be confidentialinformation on some of the microfiche and the company may want to haveit readily available for copying.

Still another consideration is existing customer habits. For example, aservice or repairman conventionally has a number of very large bookscontaining pictures of assemblies and long listings of parts. If thesebooks are reproduced on microfiche, the arrangement of the microficheshould be such that the service or repairman may follow substantiallyhis existing habit patterns, when using his books.

Accordingly an object of the invention is to provide new and improvedmicrofilm photographic image utilization devices. Here an object is toprovide photographic image utilization devices which do not require and,in fact prevent, the user from manually handling any individualmicrofiche.

Still another object of the invention is to provide microfilmphotographic image utilization devices which are sturdy, foolproof, andyet of such low cost that they may be distributed to widely scatteredpoints, even where the microfilm usage at any given point is relativelylittle.

Yet another object of the invention is to enable a ready printing, callup, and display of large catalogs on compact microfilm rolls of film.Here, a specific object is to provide parts lists for service orrepairmen or for centralized parts centers. Thus, an object is toprovide microfilm photographic image utilization devices which willfunction well, even in the hostile (relative to photographic equipment)environments, such as a garage, for example.

In keeping with an aspect of the invention, these and other objects areaccomplished by a microfilm photographic image utilization device inwhich all images are printed on a roll of film. The photographic imageutilization device has an automatic call up feature so that any givenphotographic area may be selected and projected responsive to the pushof a button or the operation of another suitable switch. Amicroprocessor provides the logic for an automatic control of themovement of a film transport mechanism to position a selectedphotographic area in a viewing area where it is held stationary, while alens is moved to project a selected image on that photographic area. Amanual back up system enables user access to information recorded on thefilm, even after a malfunction of the selection system.

A preferred embodiment of such a photographic image utilization deviceis shown on the attached drawings wherein:

FIG. 1 is a perspective view of a roll film microfilm photographic imageutilization device incorporating the principles of the invention;

FIG. 2 is a schematic layout of a strip of roll film, having a pluralityof photographic areas, each with an orthogonal array of images recordedthereon with a special bar code printed along an edge of the film andlocated near the photographic area which it identifies;

FIG. 3 shows an exemplary bar code used to identify each photographicarea on the roll;

FIG. 4 is a graphical representation of how the bar code is read;

FIGS. 5 and 6 graphically represent a preprogrammed sequence oftransport movement as the film is driven, reeled, and then brought to astop;

FIG. 7 is a block diagram of an electronic system for controlling themicrofilm photographic image utilization device of FIG. 1;

FIG. 8 is a logic diagram of a control circuit used to complete theblock diagram of FIG. 7;

FIG. 9 is a speed vs. torque graph which illustrates how the film isbrought up to speed without loss of tension;

FIG. 10 is a graph which helps to illustrate how a tension is maintainedin the film;

FIG. 11 schematically represents and explains how the roll of film istransported;

FIG. 12 is a side elevation view, taken along line 12--12 of FIG. 11,for explaining how the film moves between a pair of glass flats;

FIG. 13 is a perspective view of a lens mount and light source supportmechanism for selecting and displaying any image on a given photographicarea;

FIG. 14 illustrates a lens focusing device used on the mechanism on FIG.13;

FIG. 15 graphically and schematically illustrates how any given image ona photographic area is projected onto a photographic image utilizationdevice screen; and

FIG. 16 is a series of three graphical presentations which furtherillustrate how the images of FIG. 15 are projected onto the photographicimage utilization device screen.

Briefly, the photographic image utilization device comprises a hood 50,a film transport mechanism 51, and a control panel 52. The hood 50includes a rear illuminated screen 54, in front of a cavity large enoughto sustain a beam of light which contains the projected microfilm image.

The transport mechanism includes a supply (relative to forward filmtransport) roll or reel 56, a take up roll or reel 58 and a web, hereshown in the form of a length of film 60 extending therebetween.Preferably the reels 56, 58 have spools, hubs, or film cores with aslarge a diameter as possible so that there will be a minimum of internalworking within the film itself. Any suitable number of guide rollers mayalso be provided (as shown at 62, 64) to convey the web or film 60smoothly and evenly through the photographic image utilization device.As the web or film travels between rollers 62, 64, it passes between twoflat glass plates 66, 68 (usually called "glass flats") which areclosely spaced to hold the film, and therefore the microfilm images, ata precisely positioned, vertically oriented location relative to thelens systems (not seen in FIG. 1).

In order to load a web or strip, such as film 60, into the photographicimage utilization device of FIG. 1, the web or strip is pulled from thehub, reel, or core 56, passed between the glass flats 66, 68 andattached to the hub, reel or core 58. The hubs, reels, or film cores areinternally keyed so that they will not fit over spindles located in thecavities 70, 72, unless they are properly positioned and the web, stripor film is properly oriented.

Cover plates (not shown) may be provided to prevent accidental removalof the film and to prevent entry of dirt or other foreign matter intothe cavities 70, 72. For security, these cover plates may be protectedby a lock and key.

The control panel 52 includes a photographic area selector in the formof a plurality of push buttons 74 and a rotary switch 76. The rotaryswitch may be turned to select a book and the push buttons may beoperated to select a chapter in that book. In the example of a largeservice parts center, the book might be "lawn mowers" and the chaptermight be "engines". Therefore, the switches 76, 74 may be markeddirectly with these words. This way, the service or repairman using thephotographic image utilization device may follow his customaryprocedures of selecting book and chapter, which procedures heconventionally followed before he received the microfilm.

Any other additional control, such as switch 75, may be provided toswitch the photographic image utilization device or lamp off/on or tocause any other suitable functions.

Once the photographic area representing the first selective dimension (abook and chapter) has been automatically delivered to a reading orviewing position, it remains stationary. The operator grasps a handle 77and moves it in second and third dimensions over an index printed onplate 78. When handle 77 reaches a selected point, a desired index onthe plate 78 appears in a window 80 associated with handle 77, and acorresponding page or image on a photographic area on film 60 isprojected onto the photographic image utilization device screen 54.

A special "plus one" push button 81 is provided to extend the chapter byadvancing the film transport to display the next photographic area, whena chapter contains more than one of such areas. When the film reachesthe last photographic area in a chapter, the roll of film automaticallyrewinds to again present the first photographic area in the selectedchapter, if the "plus one" button 81 is again pushed.

A thumb wheel 82 on handle 77 may be turned to focus the image projectedonto the screen 54.

FIG. 2 shows a small section of film 60 and illustrates how thephotographic areas are arranged thereon. In greater detail, eachphotographic area (85, for example) may have any convenient length "L"and a width "W", approximately equal to the width of the film, withsuitable allowance for margins. Each photographic area includes a numberof individual images (one of which is outlined at 86 for easyidentification). The images on the photographic area are arranged in anorthogonal layout. A suitable index or table of contents may be providednear one edge of each photographic area, as indicated by cross hatchingat 88.

The drawing has been marked at 90, by way of example to indicate thatthe images on photographic area 87 are "Book 6, Chapter 9", which isalso indicated by the bar code 92. The letter "A" on photographic area85 implies that chapter 9 is so large that it extends over a pluralityof photographic areas. The user realizes that he must go on to anotherphotographic area and he pushes the special "plus one" push button 81(FIG. 1) to cause the photographic image utilization device to advancefrom photographic area 87 to photographic area 85, where a specialsingle mark bar code 89 is encountered. If the "plus one" push button 81is pushed again, the transport advances a second time, looking foranother single mark bar code. This time, however, a standard bar code 91is found. Therefore, the second operation of the "plus one" push button81 causes the film to briefly rewind and to again display the initialphotographic area 87 in Chapter 9. This "plus one" process of advancingto the next photographic area, one at a time, may be repeated as oftenas required.

A series of bar codes (such as 89, 92, 91) is printed along one marginof the film and precisely located at the same relative positions neareach photographic area. Therefore, if the bar code 92, for example, isprecisely positioned by the film transport mechanism so that a sensor isat one edge, such as 93, of the code 92, the photographic area 84 isprecisely located in the viewing area or in the optical path of thephotographic image utilization device.

The nature and function of the bar code is shown in FIG. 3. There are anumber (here nine) of spots or marks arranged in a series. Each binary"1" is a wide spot or mark, as at 98, and each "0" is a narrow spot ormark, as at 100. Each wide spot 98 is exactly twice as wide as a narrowspot 100. A pair of sensors or transducers 104, 106 are positionedadjacent the edge of film 60 to read the bar code as the film passesadjacent them. For example, if the spots or marks 98, 100 are dark areasrecorded on transparent film (or transparent marks on dark film), thesensor or transducers 104, 106 may include ligh sources on one side ofthe film and photocells on the other side of the film. The width of thespace 107 between each spot or mark is exactly the same as the width ofa narrow spot 100. The sensor or transducers 104, 106 are separated by adistance 108 which is exactly equal to 1.5 times the width of a narrowspot or mark 100.

According to the invention, it is totally irrelevant whether the filmtravels from left to right or from right to left. Neither direction ispreferred. However, it is convenient to have an expression fordistinguishing between these two directions. Therefore, one direction isarbitrarily called "forward" and the other "reverse". This samearbitrary terminology is used to identify "forward" and "reverse" motorswhich drive the film in those respective directions.

It should be noted that B sensor or transducer 104 encounters the barcode 92 before the A sensor or transducer 106 encounters it, when thefilm travels in a forward direction. The A sensor encounters the barcode first when the film travels in the reverse direction. There is noproblem, however, since the A sensor drives into one side of a shiftregister and the B sensor drives into the other side of that same shiftregister. The same output conductors are marked by the shift registerregardless of which way it is driven.

FIG. 4 graphically shows how the outputs of the sensors or transducersare interpreted by the associated electronic control circuits. (There isno correlation between the codes of FIGS. 3, 4.) The sensor output pulse109 is wide, responsive to a wide spot or mark. A narrow spot or mark100, produces a narrow pulse 110, and a space 107 between spots or marksare indicated by narrow spaces 111 between pulses. The relative widthsof the pulses and spaces, and of the distance between the sensors ortransducers are indicated in FIG. 4 by "X", "2X" and "1.5X". Each barcode has a guard zone 112 on one end, in which zone another bar code isforbidden. At any distance beyond the end of this guard zone which isgreater than 2X (i.e., more than a wide spot or mark), a new bar codemay begin. Therefore, a photographic area does not have to have a fixedand standard length. There is no need for a guard zone on the other endof the bar code because that space is protected by the next adjacent barcode.

The output of sensor or transducer B is shown by curve B of FIG. 4 andthe output of sensor or transducer A is shown by curve A. Note that theoutput A is the same as the output B, except that there is a lag of 1.5X between the two outputs. If the direction of film travel is reversed,the pulses in curve B will lag after those in curve A, because thesensor A encounters the bar code before sensor B encounters it inreverse film travel.

The sensor or transducer having the lagging output functions as a clockor strobe for reading the leading transducer. This way, it is notnecessary for a clock to maintain a precise synchronization between thefilm transport and the code photographic image utilization device. Ingreater detail, curve A has been marked with arrow heads to indicatewhether the transitions in the output of sensor or transducer A aregoing positive or going negative. In this example, the associated logiccircuitry is arranged to read the output of the B sensor or transducer,each time that the transition in the output of the A sensor ortransducer is going positive, as at 117, for example. Curve B is markedat the left-hand end to indicate the voltage levels representing a "1"and a "0".

By inspection, it will be seen that curve C represents the state of theoutput of the B sensor or transducer, at the instances when the positivegoing transitions occur in the output of the A sensor or transducer.Thus, the logic circuitry "sees" the binary word "101100", as indicatedby Arabic numerals below curve C. By recalling that each wide pulse incurve B is a binary "1" and that each narrow pulse is a binary "0", itis apparent from an inspection of FIG. 4 that the code originally readby the B sensor or transducer has been correctly interpreted by thelogic circuitry.

The start and stop of a bar code is represented by curve D andcontrolled by the negative going transitions in the output of the Asensor. The first negative going transition 113 in the output of the Asensor or transducer triggers a start of code detection, as indicated at114 in curve D. As long as the bar code continues to be read from thefilm, the control circuitry counts and responds to negative goingtransitions, and curve D remains "high". After the negative goingtransition counter reaches a specific count, the sensors have read thelast output in a bar code; therefore, on the negative going transition115, which indicates an end of a bar code, the curve D goes from "high"to "low", as indicated at 116. The end of code signal 116 occurs on thesixth negative going transition (curve A) in FIG. 4 or the ninthtransition in the code of FIG. 3. Since the number of spots or marks arethe same in all bar codes, there is a parity check because the propernumber of spots or marks must be registered at the time when curve Dgoes negative. (In the example here given, the parity check occurs whenthe circuit counts the correct number of down going transitions betweenedges 114, 116, inclusive).

The film is transported responsive to an operation of switches oncontrol panel 52, to automatically select and display a desiredphotographic area. More particularly, FIGS. 5, 6 help explain how a rollof film is transported, in order to bring a selected photographic areainto the viewing area in the photographic image utilization device ofFIG. 1 responsive to a reading of the bar codes of FIGS. 2-4. FIG. 5graphically shows film 60 traveling a forward direction and FIG. 6 showsthe same film 60 traveling in a reverse direction.

At an instant when a read command is first received, the photographicimage utilization device does not always known whether the requestedimage is on the left or the right of the viewing area since film 60 willbe resting at its last stopping place. For example, the photographicimage utilization device may lose its stored memory if power isinterrupted or switched off. Therefore, if the memory of the last readbar code is stored, the photographic image utilization device may alwaysstart in the correct direction. But, if that memory has been lost, thephotographic image utilization device starts in one preferred direction.One or more bar codes are read, and the electronic control circuitdecides whether the film is or is not traveling in the correctdirection. If it is, the film continues to so travel. If not, the filmtransport reverses direction.

In either direction of travel, it is always necessary for the film tostop at the same position relative to the bar code. For example, asFIGS. 2 and 3 are drawn, it is desirable for the film to always stopwith the A sensor or transducer head 106 (FIG. 3) aligned with the lefthand edge 93 of the bar code 92, regardless of whether the film travelsin a forward or reverse direction.

FIG. 5 shows how the film is so stopped from the forward travel motion,184. Initially, the film transport is commanded to travel at a highsearching speed. When the control circuit first recognizes a bar codecorresponding to its commanded code, the film transport may be travelingat a very high speed if it has been running long enough to get up to itsmaximum speed. Since the transport mechanism is a mechanical device withinertia, the film 60 may coast one or more bar codes beyond the desiredphotographic area. Therefore, when the transport does stop, it reversesdirection 186, and thereafter travels at a slow speed. When the desiredbar code is again recognized, the transport is stopped once more. Atslow speed, inertia does not carry the transport as far as it does athigh speed. However, the film may still coast by at least some discretedistance. Therefore, the transport mechanism reverses (188) direction apredetermined number of times (here up to six times) in a preprogrammedsequence, moving the film slightly less on each reversal, until theleading edge 93 of the bar code is precisely under the A sensor ortransducer head 106. Accordingly, the edge 93 oscillates under sensor Ain diminishing amounts of travel.

When the film is traveling in the reverse direction (FIG. 6), thecontrol circuit again looks for a bar code corresponding to its commandcode. However, it would be expensive and awkward to require the homingto be performed in two different ways depending upon the direction offilm travel during high speed searching. Therefore, once the bar codecorresponding to the command code is encountered during high speedsearching in the reverse direction 189, the transport mechanism firstreverses its direction of travel without immediate effect and before thepreprogrammed stopping sequence begins. This means that even on reversedirection searching, the film is traveling in forward direction 184 whenthe stopping sequence is initiated. Thereafter, the stopping sequence isthe same as the sequence used in the forward direction.

The electronic control circuit is seen in FIGS. 7, 8. Briefly, therotary and push-button switches 74, 76 (FIG. 7) send the command codesignals into a microprocessor 192, which may be any of many commerciallyavailable products. While any of these products may be used, theinvention currently employs the well known F8 microprocessor systemcomponents made by the Fairchild Camera & Instrument Corporation. TheA,B sensors or transducers 106, 104 transmit the sensed signals (FIG. 4)into the microprocessor 192 via switching amplifiers 194, 196. Themicroprocessor energizes a glass flat solenoid 197 via a driveramplifier 198. The microprocessor controls the direction of film travelby selectively energizing "FWD", "GO" and "REV" wires 200. The "FWD" and"REV" wires are energized with a steady d.c. potential to select thedirection of film transport travel. The "GO" wire is energized witheither a steady d.c. potential to command the forward (F) and reverse(R) motors 202, 204 to turn at high speed or with an interrupted d.c.potential to command the motors to turn at a low speed. The actual lowspeed depends upon the percentage of a duty cycle during which the GOwire is marked with the interrupted d.c. potential. These commandsignals are fed to the motors 202, 204 via two individual drivingamplifiers 206, 208, which are essentially "AND" gates.

Each of the motors 202, 204 is mechanically connected in any suitablemanner to drive one of the associated film cores. Forward motor 202drives the take up film core 58 (FIG. 1) and reverse motor 205 drivesthe supply film core 56.

FIG. 8 shows the logic diagram of an electronic control circuit whichmay be used to complete the block diagram of FIG. 7. The controlswitches 74, 76 are part of a matrix 212.

The matrix 212 comprises horizontal and vertical multiples defining aplurality of crosspoints. Each switch 74, 76 has a set of contactsconnected across the matrix crosspoints. For example, one set of switchcontrolled crosspoint contacts, shown at 209, are here assumed to be theonly ones closed by an operated push button 74. Of course, any othercrosspoints could also be the closed ones.

Scanner 210, which may be part of the microprocessor, initially appliedground G to the upper most horizontal H1 in matrix 212. All otherhorizontals are marked with the positive potential P1. All verticals aremarked with positive potential P2.

Scanner 211, which may also be part of the microprocessor, sequentiallytests the potential on each vertical in matrix 212, and finds onlypotential P2 because the above assumption, in this description, has beenthat only crosspoints 209 are closed.

After scanner 211 completes one scan, the scanner 210 is operated toremove ground G from the uppermost horizontal H1 and to apply it to thenext lower horizontal H2. The scanner 211 finds potential P2 on verticalV1. However, vertical V2 is connected through contacts 209, assumed tobe closed, to ground G.

Immediately, the control circuit recognizes that it has found the closedpush-button contact and scanner 210 is advanced in its cycle to applyground G to horizontal H5. Again, the scanner 211 searches for a groundapplied through a selected set of contacts on rotary switch. If theclosed rotary switch contact is on horizontal H5, the control circuitstops the scanners. If not, scanner 210 is advanced to apply ground G tohorizontal H6 and scanner 211 searches for it.

It should now be apparent that the matrix 212 enables the electroniccircuitry to ascertain the commanded code responsive to a selectiveoperation of a push button 74 and rotary switch 76.

The logic of the microprocessor 192 is represented at 214. Forcompleteness FIG. 8 repeats the sensors or transducers 104, 106, glassflat solenoid 197 and amplifiers 194, 196, 198. Each of the sensoramplifiers 194, 196 include a buffer amplifier 216, 218 followed byindividually associated trigger circuits 220, 222, preferably Schmitttriggers. This way, the logic circuitry 214 receive unambigeous sensororiginated signals (FIG. 4) responsive to each detection of a bar codespot or mark.

The remainder of FIG. 8 shows a circuit for driving the film transportmechanism and for maintaining film tension. This portion of the figureis divided by a dot-dashed line 224, with the driving amplifier 206shown above the line and driving amplifier 208 shown below the line.Since circuits 206, 208 are the same, only circuit 206 will beexplained.

The forward FWD and reverse lines REV are connected to individuallyassociated AND gates 226, 228. Thus, the AND gate 226 conducts when themicroprocessor 192 energized the FWD and GO wires. The AND gate 228conducts when the microprocessor energizes the REV and GO wires.

The output of AND gate 226 is fed into an OR gate 230 which energizes amotor drive circuit 232. The motor drive circuit supplies a d.c. voltageto forward motor 202. If the motor 202 is in the fast drive mode, thereis a steady state d.c. potential. The microprocessor 192 energizes theGO wire continuously and without interruption. Drive circuit 232 thenapplies a maximum d.c. power to the motor 202, which runs at high speed.

When the desired bar code is detected, the motor 202 is stopped. Themicroprocessor signal for stopping the motor is a simultaneousenergization of the FWD, REV and GO wires, so that the two motors pullagainst each other. The potential on the GO wire is interrupted, firstslowly and then at a progressively faster rate. After the frequency ofinterruptions passes a critical high frequency rate, the system can nolonger follow the interruptions and the motors stop with the initiallyundriven motor acting as a drag upon the film to maintain film tensionand help stop the driven motor.

If the motor 202 is then driven in a slow drive mode, there is a problemsince frictional forces may vary from time to time. for the same slowspeed, the amount of energy supplied at any given time may vary from theamount that must be supplied at any other time. Accordingly, when thecombination of signals sent from the microprosessor logic 214 over theFWD and GO leads to motor drive circuit 232 indicates a slow speed, themotor drive circuit 232 preferably applies energy to the motor in themanner indicated by FIG. 9, wherein speed is shown on a vertical scaleand torque on a horizontal scale. Initially, a very low voltage isapplied to forward motor 202 at a potential which is here arbitrarilydesignated "X". If the motor does not turn, the potential is graduallydoubled to "2X". If it still does not turn, the voltage is increased to"3X", etc. Eventually, the motor begins to turn.

In order to so increase the potential applied to the motor 202, the slowspeed indicating intermittent interruptions on the GO wire begin asnarrow pulses which are gradually made wider, with a rising ramp frontcharacteristics. As the GO wire is energized during progressively longerperiods in the interruption duty cycle, the motor 202 runs atprogressively faster (but still relatively slow) speeds. Hence, as soonas the instantaneous friction is overcome in the motor, it starts slowlyand thereafter builds speed, with the acceleration characteristicsdepicted by line 233 in the graph of FIG. 9.

Whenever either motor (the driven motor) is operating to pull the film,the other motor (the undriven motor) is energized with a weak current.The undriven motor supplies only enough torque to act as a drag andthereby maintain film tension. The control of this drag is extremelyimportant since it maintains a uniform film tension. Otherwise, theturns of film on a reel might alternately loosen and cinch, andtherefore, damage the film. Accordingly, there is a need for themicroprocessor to precisely control the current supplied to the undrivenmotor.

FIG. 10 explains how the current supplied to the undriven motor iscontrolled and regulated to maintain a predetermined film tension. Ingreater detail, when the motor is first energized, it draws currentwhich shoots up from a zero axis to the point 240, FIG. 10A. As themotor beings turning, the current falls off, with some decayingcharacteristics, as indicated between the points 240, 242.

Current sensor 244 is a trigger circuit connected to the output of themotor drive circuit 232 to detect current drawn by the motor, asdepicted in FIG. 10A. The sensor 244 detects when the current falls tothe point 242, and thereupon sends a signal over wire 250 to AND gate252. The other input of AND gate 252 is already energized via the FWDwire and the output of AND gate 226. Thus, when the forward motor 202 isoperating, AND gate 252 applies a signal through OR gate 254 to motordrive circuit 256 and reverse motor 204.

Upon energization, reverse motor 204 acts as a drag upon film 60 andtherefore upon forward motor 202, which must then draw more current fromthe motor drive source 232. Current sensor 244 uses a trigger circuitwhich switches OFF when there is an increase of current in the motor202. The current to reverse motor 204 is removed. Thus, the motor drivecircuit 256 has received a pulse of driving current, as indicated bypulse 258 (FIG. 10B). A deenergization of the reverse motor 204 reducesthe drag upon film 60 and forward motor 204, and the cycle repeats.

The motor drive circuit may also operate on an analog basis, if desired.

An advantage of the above-described invention is that the transport iscompletely free of brakes, clutches, and the like, which are notorioussources of trouble. More particularly, the film 60 follows the path fromreel or core 56, over rollers 62, 64 to reel or core 58. Motor 202drives the film 60 in a forward direction and motor 204 then receives avery light current so that it acts as a drag or brake upon the film.Likewise, motor 204 drives the film in an opposite or reverse direction,at which time motor 202 receives a light current so that it acts as adrag or a brake. This way, one motor always acts to maintain filmtension while performing the clutch and braking functions.

Hence, as long as the driven forward motor 202 continues running (CurveA, FIG. 10), its energizing current fluctuates while motor 202 hunts forits correct speed, as shown at 260. The undriven reverse motor 204 ispulsed, as shown at 262, responsive to current fluctuations 260. Thus,the undriven motor receives a low level d.c. energy, which is anintegration of and derived from an average of the pulses 262. This lowlevel of current causes the reverse motor 204 to resist turning andthereby maintains a steady tension upon the film 60.

Between the outputs of AND gates 226, 228 there is an interlock circuitdesigned to keep the motors from being driven at any time when themechanical parts of the photographic image utilization device are not ina condition for the film to travel safely. In greater detail, aplurality of any suitable mechanical switches 264 are connected inseries between ground and a voltage divider comprising resistors 266,268, 270. These switches 264 may be "Microswitches" actuated bymechanical photographic image utilization device parts, such as themovable glass flat 68, film reels 56, 58 or any other mechanical parts,all of which should be in a normal condition before the film may besafely transported. If all of the switches 264 are properly closed,ground is applied to the base of transistor 272, which switches off.Thereafter, the outputs of AND gates 226, 228 may be effective upon themotors 202, 204. However, if one or more of the interlock switches 264is opened, the potential set by voltage divider 266, 268, 270establishes a base bias which switches on the transistor 272, to applyground to a junction between diodes 274, 276, which are connected to theoutputs of AND gates 226, 228, respectively. Thereafter, the outputs of"AND" gates 226, 228 are clamped to ground, and the motors 202, 204cannot be commanded to operate.

When the electronic control circuit of FIG. 8 finally stops the film, adesired microfiche is accurately positioned in a viewing positionbetween the glass flats 66, 68 (FIG. 11). More particularly, the barcode reading head sensors or transducers 104, 106 are located at anyconvenient point along the travel path for film 60. FIG. 11 shows the A,B sensors 106, 104, respectively, at a location near the right-hand endof glass flats 66, 68. For example, if the bar code 92 (FIG. 2) isprinted at a proper position on the film 60, photographic area 87 isprecisely positioned between glass flats 66, 68, when one edge 93 (FIG.2) of the bar code is directly under one of the sensors (here assumed tobe A sensor 106). Preferably, each sensor comprises a light sourcebeneath the film, and a matching photocell above the film. Of course,the projector light source of the reader is also below the film;therefore, the sensors might also be simple photocells positioned abovethe film. Also, this arrangement of sensor locations may be changed, inany convenient manner. FIG. 11 shows the glass flats 66, 68 in a closedor reading position. In this position, a lens holder 300 floats looselyon the top of the upper glass flat 68. However, the film 60 might bescratched if it is pulled between the flats while they are clamped shut,and it is desirable to open the flats during film transport. Anysuitable means (not shown) automatically moves the lens holder 300 fromthe reading position on top of the movable glass flat 68, either beforeor as it opens.

Means are provided for manually selecting the desired photographic area.In greater detail, as here shown, the film core 56 is normally driven bymotor 204, acting through a set of reducing gears 295. The film core 58is normally driven by motor 202, acting through its set of reducinggears 296. This way, the film may be driven in either direction, by asuitable energization of one of the motors. Film tension is maintainedby a low level of current energizing the other motor. If there is a needto override the motors or to operate the reader without the motorassist, each film core 56, 58 has a one way clutch 297, 298 individuallyassociated therewith. If clutch 297 is turned by hand in the directionindicated by the arrowhead, film is pulled from film core 58 and woundupon the film core 56. The one way action of clutch 297 prevents theuser from turning the film core in the wrong direction and therebyloosening film tension. Also, a resistance to turning is naturallysupplied by the unenergized motor 202, gear reduction 296 and othermechanical parts, in order to supply film tension. Likewise, if clutch298 is turned by hand, film is pulled from core 56 and wound upon core58, with film tension maintained in a similar manner.

As seen in FIG. 12, the upper glass flat 68 is spring biased at 302 to anormally open position. When it is time to read or project an image, aglass flat solenoid 197 is energized to attract an armature 304, andthereby close the movable glass flat 68 against the lower or fixed flat66. Of course, the movable glass flat 68 could also be normally springbiased to a closed position and opened by the solenoid 197. The normallyopen position shown in FIG. 12 is preferred because it tends to savecurrent, is more fail-safe because film is less likely to be pulledthrough closed flats, and because it is easier to load the film into thereader if the glass flats are normally standing open.

FIG. 13 shows the mechanical structure which is used to select andproject the photographic area image which is to be displayed. This imageselecting mechanism comprises a yoke 332 mounted on a transportmechanism comprising a pair of horizontal bars 334 and sliding block336. The sliding block rides in any suitable channel 338 which isrigidly attached to the reader of FIG. 1, to slide back and forth indirections V and W. For example, the slide may be somewhat similar tothe slides conventionally used to mount file cabinet drawers.

At one end, each of the two bars 334 are rigidly mounted in and movewith the block 336 and as it travels back and forth in the V-Wdirections. The opposite ends of bars 334 are rigidly attached to ablock 340 which freely rests, under gravity, on the index plate 78(FIG. 1) of the reader. A small foot or glider 342 is formed on thebottom of block 340 so that it slides with little friction in directionsV-W.

The yolk 332 slides freely, in directions X-Y, along the length of thetwo bars 334. Therefore, if the handle 77 and therefore the yolk 332 ismoved, an indexing mechanism (window 80) may be moved to any selectedplace on the index plate 78. This movement places lens holder 300directly over the selected image.

It should be noted that one form of lens transport structure 338, 339enables the lens-scanning and projecting system to scan in one (V-W)direction and that another form of lens transport structure 334 enablesthe lens system to scan in a perpendicular direction (X-Y).

Thus, the lens may be moved over an area to any point in a plane definedby these two perpendicular directions. It is almost impossible for twosuch different transparent structures, which are isolated from eachother, to present the same frictional forces to resist movement of theassembly. For example, the foregoing description has indicated that theslide 336 is similar to a file cabinet slide mount, which is a lowfriction mount, while yoke 332 is merely described as sliding along twobars. Hence, it is apparent that there will almost certainly be lessfriction in the V-W direction than in the X-Y; however, the specificdirection of less friction is not important.

The important thing is that the lens transport system prefers to move inone direction as compared to the other. Therefore, the lens mount may beplaced over a selected row, and then, a light touch upon handle 77causes the lens mount to scan over all images in the selected row. Or,if the frictional forces are reversed, the light touch causes the lensmount to scan over all images in the selected column. This way, the lenstransport system tends to follow a more predictable path along a givenline and not to meander across the scanned photographic area. Hence, itis much easier to find one image, from among an orthogonal array ofimages, where the inventive lens-transporting system is used.

Another of the advantages of this inventive lens transport system isthat the image moves across the screen in the same direction that thelens holder 300 moves. Therefore, a person holding handle 77 may movehis hand in the same direction that he wants the picture to move. Hence,the image selection movement is an instinctive and reflex type ofoperation. This is in contrast to many optical systems wherein the imageis inverted or reversed. In those systems, a person must pull his handin, say, an "8 o'clock" direction in order to make the image move in a"2 o'clock" direction.

The yolk 332 has an opening 346, 347 for receiving both the glass flats66, 68 and the film 60. Neither the film nor the glass flats touch theyolk 332, itself. A light source 344 is positioned beneath the opening346, 347. In front of the light source 344 is a mirror 350 which is setat a 45° angle, with respect to the X-Y direction. Therefore, ahorizontal beam of light 352, from source 344, is reflected at a rightangle to pass vertically through the film and a lens 354, in lens holdermount 300. Accordingly, it should be clear that the lens 354 may beplaced over and the light source mirror 350 may be placed under anyselected image on the photographic area clamped between the glass flats.This way, any image on the photographic area may be projected towardscreen 54, along the optical path represented by the double dot-dashedline 352. Any suitable additional mirrors may also be included to foldthe optical path, as may be required, in order to fit it within the hood50 (FIG. 1). Of course, the mirror 350 may be removed if the lightsource 344 is aimed directly toward the lens 354. An advantage of themirror is that it may be a special coating to separate the heat from thelight.

The yoke 332 is constructed to enable the lens holder 300 to floatloosely and freely, directly upon the upper surface of the glass flat68. By resting directly upon the glass, the lens holder is alwayspositioned exactly the same distance away from the microfilm. Inside thelens holder 300 is a telescoping lens mount 355 which may be moved up ordown in order to focus the image of the photographic area upon thescreen 54.

The mechanism for focusing the lens is shown in FIG. 14. Morespecifically, the lens holder 300 is vertically oriented and the lensmount 355 arranged for telescoping motion within the holder. Adjacentthe lens mount 355 is a rotatably mounted horizontal shaft 356 having aneccentric elongation or cam 358 integrally formed thereon. The camengages the telescoping lens mount 355. Therefore, as the shaft 356rotates, the lens mount 355 moves, within the lens holder 300, up ordown in directions C-D.

A pulley wheel 362 is rigidly attached to the end of shaft 356, torotate the shaft, as the pulley wheel turns. A dial cord 364 is trainedover the pulley 362, two idler wheels 366, 366 and a horizontallyoriented pulley wheel 368. The thumb wheel 82 (FIG. 1) is mounted on andturns with the same shaft 370 that carries the pulley wheel 368.Therefore, as the thumb wheel 82 is rotated, the pulley 368 turns, topull the dial cord 364. The cord 364 turns pulley 362 to rotate shaft356 and raise or lower the lens mount 355. This entire focusingmechanism (FIG. 14) is mounted on and carried by the yolk 332 (FIG. 13).Therefore, the focusing mechanism moves with the yolk, responsive tomanipulation of the handle 77. Also, the shaft 356 may be adapted toswivel about the axis of the idler wheels 366, 366 so that the lensholder may raise or lower as the upper glass flat 68 raises or lowers.

The principle of the image selection is graphically illustrated in FIGS.15, 16. The microfiche 84 is positioned under the yolk and the lens,here graphically represented in three positions 380, 382, 384. Thescreen 54 is placed over the lens either with or without optical pathfolding mirrors therebetween. The magnification of the lens is such thattwo images 386, 388 fill the entire screen 54.

If the yolk and, therefore, the lens is moved to position 380, the imageprojected on screen 54 is oriented as shown by the three dot-dashed line390. Thus, for example, an image in the lower right-hand corner (asviewed in FIGS. 15, 16) is placed upon the screen 54. The remainder ofthe projected image 390 is lost inside the hood 50. If the yolk and lensare moved to position 382, the projected image on the microfilm is alsomoved to the position shown by the double dot-dashed line 392. This timethe two individual images 386, 388, falling on screen 54, are taken fromnear the center of the photographic area 84. Likewise, if the yolk andthe lens are moved to position 384, the projected image on the microfilmis shifted to the position shown by the single dot-dashed line 394. Thistime the two individual images 386, 388 falling on screen 54 are takenfrom the upper left-hand corner of the photographic area 84. Again, allprojected images, except those falling on screen 54, are lost inside thehood and are not seen by the viewer.

Those who are skilled in the art will readily perceive how the inventionmay be modified. Therefore, the appended claims are to be constructed tocover all equivalent structures.

The invention claimed is:
 1. A microfilm photographic image utilizationdevice for projecting a large library of images onto a viewing arearesponsive to a three-dimensional selection process, said devicecomprising a roll of film wound on first and second reels and carryingsaid large library of images, means for transporting said roll of filmin either of two directions from one of said reels to the other of saidreels, said film having a plurality of images printed thereon inindividually identified discrete photographic areas, each of saidphotographic areas having an individually associated bar code addressprinted on the film, each of said bar codes comprising an aligned seriesof wide and narrow marks separated by spaces, each narrow mark havingthe same width, each of said wide marks being twice as wide as saidnarrow marks, the width of each of said spaces being equal to the widthof said narrow marks, the individual area identification addresses givenby said bar codes constituting an index for a first selective dimension,each photographic area having a plurality of individual images arrangedin an orthogonal array, the X and Y axes of said orthogonal arrayconstituting second and third selective dimensions, means responsive todetection of a selected bar code identification of any one of theindividual area identifications for automatically driving said transportto reel said film in either of said two directions to position anyselected one of said photographic areas during a first dimensionalselection in a reading location in said large libray, and manuallymovable means comprising a movable lens which is thereafter moved in Xand Y dimensions in a manual search mode for projecting a selected imagefrom the photographic area which is then positioned within said viewingarea, said lens having an angle which is wide enough to project an imagefrom a most remote part of the photographic area onto said viewing area.2. The device of claim 1 and control means for giving an address in saidone dimension for selecting said one photographic area responsive tomovement of at least one control switch to issue a command code, saidcontrol switch being identified by the subject matter of the image. 3.The device of claim 2 and means responsive to said command code forstarting said transport means from any point on said film in search ofone of said bar code addresses corresponding to said addressing commandcode, means for detecting whether said transport means is searching inthe correct one of said two directions for said one bar code, and meansfor reversing said transport means if said transport means detects barcodes which indicate that searching is in the incorrect one of said twodirections.
 4. The device of claim 3 and means for stopping saidtransport means responsive to a detection of a bar code address of saidone dimension of movement with a preprogrammed sequence consisting of apredetermined number of diminishing oscillatory mechanical movements,said film stopping with a selected bar code address in a predeterminedstopping position.
 5. The device of claim 1 wherein said transport meansmay move at either a high searching speed or a slow positioning speedunder the control of a central controller means, and means for stoppingsaid transport means under the control of said central controller meansresponsive to a detection of the desired first dimensional address ofsaid selected one photographic area in said reading location, saidstopping means comprising means for stopping said transport means whileit is being driven at said high searching speed in one of said twodirections, means responsive thereto for thereafter driving saidtransport means in an opposite direction at said slow positioning speed,and means for thereafter initiating a preprogrammed sequence under thecontrol of said central controller for repeatedly reversing thedirection of said transport means a predetermined number of times duringsaid programmed sequence for bringing said film to a stop with saidfirst dimensional address at an exact position with a diminishingoscillatory motion.
 6. The device of claim 1 wherein said filmtransporting means is normally operated by a central controller meansand manually controlled one-way clutch means for overriding said centralcontroller means operation of said automatic reeling means by enablingthe roll of film to be rolled independently of the transporting means inorder to position the film at a manually selected position.
 7. Thedevice of claim 1 wherein said movable lens comprises yoke means movableover said orthogonal array of images while one of said photographicareas is in said viewing area and said lens means is mounted in saidyoke for projecting at least one of the images under said lens at theinstantaneous position where said yoke is located.
 8. The device ofclaim 1 and manually controlled means for moving said lens over a randompath.
 9. A microfilm photographic image utilization device forprojecting a large library of images onto a viewing area responsive to athree-dimensional selection process, said device comprising a roll offilm wound on first and second reels and carrying said large library ofimages, means for transporting said roll of film in either of twodirections from one of said reels to the other of said reels, said filmhaving a plurality of images printed thereon in individually identifieddiscrete photographic areas, the individual area identificationsconstituting in index for a first selective dimension, each photographicarea having a plurality of individual images arranged in an orthogonalarray, the X and Y axes of said orthogonal array constituting second andthird selective dimensions, means responsive to detection of a selectedidentification of any one of the individual area identifications forautomatically driving said transport to reel said film in either of saidtwo directions to position any selected one of said photographic areasduring a first dimensional selection in a reading location in said largelibrary, manually movable means comprising a movable lens which isthereafter moved in X and Y dimensions in a manual search mode forprojecting a selected image from the photographic area which is thenpositioned within said viewing area, said lens having an angle which iswide enough to project an image from a most remote part of thephotographic area onto said viewing area, said movable lens furthercomprising yoke means movable over said orthogonal array of images whileone of said photographic areas is in said viewing area, said lens meansbeing mounted in said yoke for projecting at least one of the imagesunder said lens at the instantaneous position where said yoke islocated, one-hand control handle means connected to said yoke means,whereby said lens mounted on said control handle means is movedresponsive to a manipulation of said one-hand control handle means, andmeans mounted on and movable with said one-handed control handle meansfor focusing said lens.
 10. The device of claim 9 wherein said viewingarea is a screen means in said device, said lens having a magnificationfactor adequate for projecting at least one of said images tosubstantially fill said screen.
 11. The device of claim 9 wherein saidmeans mounted on said one-handed control handle means can swivel toenable said lens mounting means to raise or lower without disconnectionof said focusing means.
 12. A control means for a transport means forreeling a long strip wound on supply and take-up means, said striphaving a plurality of discrete locations serially distributed along thelength thereof, bar code means comprising marks and spaces extendinglongitudinally along the length of said strip for individuallyidentifying each of said discrete locations by an individuallyassociated address code positioned on said strip near each of thediscrete locations, the positions of at least one of said marks in eachof said codes always having a fixed relationship with respect to thepositions of the discrete locations identified thereby, each of saidcodes including a plurality of sequentially occurring discrete one ofsaid code marks separated by uniform spacing, code reading meansconsisting of two sensors positioned adjacent said strip, each of saidsensors sequentially reading in series each discrete code mark in saidcodes and providing a corresponding output during the operation of saidtransport means, means responsive to the discrete outputs of one of saidtwo sensor means as it reads said discrete code marks for enabling theoutput of the other of said sensor means as it reads such discretemarks, means responsive to the output of said other of said sensor meansfor indicating a detection of a selected one of said address codes, andmeans responsive to said code detecting means for stopping saidtransport means.
 13. The control means of claim 12 wherein said onesensor means experiences and its output contains a matched pair ofoppositely going transitions responsive to each of said marks, and meansresponsive to transitions in one of said directions for causing saidreading of the other sensor means.
 14. The control means of claim 12wherein said strip is a reel of film, and manually movable means forselectively projecting an incremental portion of said stopped filmstrip.
 15. A rolled web manipulation and transport means for locatingone of many images assembled into a plurality of photographic meansresponsive to three-dimensional addressing, each of said photographicareas having an individually associated bar code printed on the film,each of said bar codes comprising an aligned series of wide and narrowmarks separated by spaces, each narrow mark having the same width, eachof said wide marks being twice as wide as said narrow marks, the widthof each of said spaces being equal to the width of said narrow marks,said transport means comprising means for moving said rolled web betweensupply and take-up rolls for selectively positioning any one of manydiscrete segments of said web in a display area, automatic searchingmeans for moving said web while searching for a preselected bar codeassociated with a first dimensional address, until a selected portion ofsaid web identified by said preselected bar code is positioned in saiddisplay area and for thereupon stopping said web while so positioned,and discrete display means thereafter manually movable along randompaths to second and third dimensional addresses within said displayarea, said manual movement of said display means occurring while saidweb is and remains stationary, said random paths being not necessarilyorthogonally oriented within said display area for projecting an imagefrom a selected incremental part of said web defined by a selectedthree-dimensional address where said discrete display means is locatedafter its random movement to a manually selected incremental part. 16.The web manipulation and transport means of claim 15 and glass flats forsupporting said web in a plane perpendicular to a lens which rests in afocused position upon said glass flats during periods while said web isnot moving, said glass flats moving away from said web while said web ismoving whereby said lens resting on said glass is moved away from itsfocused position, and remote control means movable with said discretedisplay means and said glass flats for focusing a lens associated withsaid discrete display means regardless of the instantaneous position ofsaid lens on said glass flats thereby accommodating movement of saidlens into and away from said focused position.
 17. The web manipulationand transport means of claim 16 wherein said discrete display meanscomprises said lens and remote control focusing means mounted on a yokehaving a space for receiving said web with said lens above the web and alight source below said web, said focusing means being controllable froma point for manipulating said yoke.
 18. The web manipulation andtransport means of claim 16 and means for projecting images at the pointwhere said movable discrete display means is located, said projectionbeing along a path extending from said web through said lens and onto animage display area, said transport means transporting said web in eitherof two directions, code responsive means for automatically reeling saidweb in either of said two directions to position a selected one of saidphotographic areas in said viewing area, control means for selecting oneof said bar codes, means responsive to said selected one code forstarting said transport means in either of said two directions in searchfor said selected one code, means for detecting whether said transportmeans is searching in the correct one of said two directions for saidone code, and means for reversing the direction of said transport meansif said detecting means detects that the transport means is searching inthe incorrect one of said two direction.
 19. The web manipulation andtransport means of claim 18 and means for stopping said transport meansresponsive to detection of said one selected bar code, said stoppingmeans comprising means for stopping said transport means while it isbeing driven at a high speed in either of said two directions, meansresponsive thereto for thereafter driving said transport means in anopposite direction at a slow speed, and means for thereafter repeatedlyreversing the direction of said transport means a predetermined numberof times according to a pre-established program for incrementallybringing said web to a stop at an exact position with diminishing webmotion on each reversal.
 20. The web manipulation and transport means ofclaim 16 wherein said remote control means is a manually controlledhandle for moving said lens, and means mounted on said handle forfocusing said lens.
 21. The web manipulation and transport mechanism ofclaim 20 wherein said focusing means is a finger-controlled wheel whichmay be turned either while said handle is being moved or while saidhandle is stationary.
 22. A microfiche photographic image utilizationdevice film transport system for use with a roll of a film mounted ontwo reels, either of which may be a supply or a take-up reel to providea bidirectional film travel, wherein successive areas on said film areidentified by individually associated series code appearing on saidfilm, said system comprising means for transporting said roll of film atrandomly variable speeds between the supply and take-up reels, saidspeeds varying with the amount of film wound upon a reel, the age andcondition of the transport, etc., means for reading said codes as saidfilm is transported at said variable speeds, first motor means fordriving said film in a first direction through said device, second motormeans for driving said film in a reverse direction through said device,electronic control means for selectively energizing both of said motorssimultaneously at different energy levels so that one of said motors mayrespond to a higher energy level by driving said film in one of saiddirections, the other of said motors responding to a lower energy andbeing overpowered by said one motor which is operating at said higherenergy level to drive said film, the other said motors acting as a dragor a brake upon said film to maintain film tension while performingclutch and braking functions, whereby said transport is electronicallycontrolled and does not require mechanical speed controllers,transmissions, brakes, or clutches, and whereby a reversing of theelectronically controlled energy levels reverses the functions of thetwo motors and thus reverse the direction of film travel, means forautomatically bringing said film transport to a halt responsive to areading of a preselected code, lens and light source means mounted to bemanually movable as a unit, and means for thereafter manually movingsaid lens and ight source as a unit for selecting and displaying anincremental portion of the individual area identified by the preselectedcode.
 23. A bar code reading system comprising a web having a pluralityof said bar codes with no specific start or stop codes, said bar codesbeing formed in a single track extending longitudinally along the lengththereof, wherein each of said plurality of bar codes consists of analigned series of wide and narrow marks separated by spaces, each narrowmark having the same width, each of said wide marks being twice as wideas said narrow marks, the width of each of said spaces being equal tothe width of said narrow marks, sensor means positioned over the singletrack extending along said web area where said bar codes are located,said sensor means comprising two reading means for sequentially readingone at a time each of said aligned series of marks at each of twolocations separated by a distance equal to one-and-a-half of the widthof said narrow marks, the sensor at one of said reading locations actingas a strobe for the sensor at the other of said locations, with strobingoccurring responsive to each code mark, and means responsive to thestrobing for indicating an encoded "1" or "0" depending upon the readingthen being received at the strobed location.